$(document).ready(function() {
    // 获取所有需要预加载的悬停图像URL
    var hoverImages = [];
    
    // 查找所有有:hover伪类或data-hover属性的元素
    $('[data-hover], :hover').each(function() {
        var hoverImage = $(this).css('background-image') || 
                        $(this).attr('data-hover') || 
                        $(this).attr('hover-src');
        
        if (hoverImage) {
            // 提取URL（去除CSS的url()包装）
            hoverImage = hoverImage.replace(/^url\(["']?/, '').replace(/["']?\)$/, '');
            hoverImages.push(hoverImage);
        }
    });
    
    // 去重
    hoverImages = [...new Set(hoverImages)];
    
    // 预加载所有图像
    $.each(hoverImages, function(index, imageUrl) {
        $('<img/>')[0].src = imageUrl;
    });
});

function preloadHoverImages() {
    var sheets = document.styleSheets;
    var images = [];
    
    // 遍历所有样式表
    for (var i = 0; i < sheets.length; i++) {
        var rules = sheets[i].cssRules || sheets[i].rules;
        if (!rules) continue;
        
        for (var j = 0; j < rules.length; j++) {
            if (rules[j].selectorText && rules[j].selectorText.indexOf(':hover') !== -1) {
                var bgImage = rules[j].style.backgroundImage;
                if (bgImage && bgImage !== 'none') {
                    var url = bgImage.match(/url\(['"]?(.*?)['"]?\)/)[1];
                    images.push(url);
                }
            }
        }
    }
    
    // 预加载图像
    $(images).each(function() {
        $('<img/>')[0].src = this;
    });
}

$(document).ready(preloadHoverImages);

document.addEventListener('DOMContentLoaded', function() {
    var links = document.querySelectorAll('link[rel="stylesheet"]');
    links.forEach(function(link) {
        var sheet = link.sheet;
        if (sheet) {
            var rules = sheet.cssRules || sheet.rules;
            if (rules) {
                Array.from(rules).forEach(function(rule) {
                    if (rule.selectorText && rule.selectorText.includes(':hover')) {
                        var bg = rule.style.backgroundImage;
                        if (bg && bg.includes('url(')) {
                            var img = new Image();
                            img.src = bg.match(/url\(['"]?(.*?)['"]?\)/)[1];
                        }
                    }
                });
            }
        }
    });
});